As evidenced by representative U.S. Pat. No. 4,048,690 (Wolfson--9/20/1977), the prior art recognizes that previously unattainable dental cleaning benefits are attainable with "twinbrushes rotary toothbrushes" wherein the twin-brushes angular reciprocate in unison. During each co-angular reciprocation of the twinbrushes, the following gingival area cleaning simultaneosuly occurs at the bucal and lingual teeth sides: at the first angular movement, inimical plaque is abradably removed; and at the second angular movement, said removed plague particles are swept directionally away from the sensitive gingival sulcus. Moreover, another heretofore unattainable cleansing simultaneously occurs to the bucal and lingual sides during each co-angular reciprocation of the twin-brushes, namely the vertically extending inter-proxial juncture areas of adjacent teeth are cleansed directionally away from the sensitive gingival sulcus.
Although U.S. Pat. No. 4,048,690 describes "twin-brushes rotary toothbrushes" that have theoretically solved the aforementioned dental cleaning problems, it teaches a bulky and structural mounting and actuation for the twin-brushes and to the extent that a so constructed twin-brushes rotary toothbrush is too large to fit and operationally function within the mouth of persons anatomically endowed with average or small size mandible.
And although U.S. Pat. No. 4,048,690 does teach usage of auxilary bristles (and located between the twin-brushes) for simultaneously cleaning teeth occlusial surfaces, it is difficult for the operator to simultaneously reciprocate the auxiliary occlusial brushes and the bucal/lingual twin-brushes.